Association of Enterococcus spp. with Severe Combat Extremity Injury, Intensive Care, and Polymicrobial Wound Infection.

BACKGROUND: Combat-related extremity wound infections can complicate the recovery of injured military personnel. The Enterococcus genus contains both commensal and pathogenic bacteria found in many combat wounds. We describe the patient population susceptible to Enterococcus infection, the characteristics of Enterococcus spp. isolated from combat-related wounds, and the microbiological profile of Enterococcus-positive wounds. METHODS: Patient and culture data were obtained from the Trauma Infectious Disease Outcomes Study. Subjects were divided into a case group with enterococcal extremity wound infections and a comparator group with wound infections caused by other micro-organisms. RESULTS: Case and comparator subjects had similar patterns of injury and infection. Case subjects had higher Injury Severity Scores (33 vs. 30; p < 0.001), longer hospitalization at U.S. facilities (55 vs. 40 days; p = 0.004), and required more large-volume blood transfusions (>20 units) within 24 h post-injury (53% vs. 30%; p < 0.001). Approximately 60% of case subjects had three or more infections, and 91% had one or more polymicrobial infections, compared with 43% and 50%, respectively, in the comparator group. The thigh was the most common site of Enterococcus spp. isolation, contributing 50% of isolates. Enterococcus faecium was the predominant species isolated from case-group infections overall (66%), as well as in polymicrobial infections (74%). Frequent co-colonizing microbes in polymicrobial wound infections with Enterococcus were other ESKAPE pathogens (64%) (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae [and Escherichia coli], Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and fungi (35%). CONCLUSIONS: The specific pathogenicity of Enterococcus relative to other pathogens in polymicrobial wounds is unknown. Identifying strain-specific outcomes and investigating the interactions of Enterococcus strains with other wound pathogens could provide additional tools and strategies for infection mitigation in combat-related wounds.

Accurate and Rapid Differentiation of Acinetobacter baumannii Strains by Raman Spectroscopy: a Comparative Study.

In recent years, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has become the standard for routine bacterial species identification due to its rapidity and low costs for consumables compared to those of traditional DNA-based methods. However, it has been observed that strains of some bacterial species, such as Acinetobacter baumannii strains, cannot be reliably identified using mass spectrometry (MS). Raman spectroscopy is a rapid technique, as fast as MALDI-TOF, and has been shown to accurately identify bacterial strains and species. In this study, we compared hierarchical clustering results for MS, genomic, and antimicrobial susceptibility test data to hierarchical clustering results from Raman spectroscopic data for 31 A. baumannii clinical isolates labeled according to their pulsed-field gel electrophoresis data for strain differentiation. In addition to performing hierarchical cluster analysis (HCA), multiple chemometric methods of analysis, including principal-component analysis (PCA) and partial least-squares discriminant analysis (PLSDA), were performed on the MS and Raman spectral data, along with a variety of spectral preprocessing techniques for best discriminative results. Finally, simple HCA algorithms were performed on all of the data sets to explore the relationships between, and natural groupings of, the strains and to compare results for the four data sets. To obtain numerical comparison values of the clustering results, the external cluster evaluation criteria of the Rand index of the HCA dendrograms were calculated. With a Rand index value of 0.88, Raman spectroscopy outperformed the other techniques, including MS (with a Rand index value of 0.58).

Maggot debridement therapy in modern army medicine: perceptions and prevalence.

Maggot debridement therapy (MDT), despite its long history and safety profile, finds limited use in the military health care system. Although new methods are continually being investigated to debride wounds more quickly and effectively, MDT remains largely a therapy of last resort. We evaluated the frequency of MDT in the Army sector of the MHS and the decision-making process surrounding its use. A 22 question survey of Army physicians was prepared and distributed through select Medical Corps Consultants in specialties likely to practice debridement. 83% of respondents were familiar with MDT, and of those familiar, 63% were aware of FDA approval for the product and 10% had used the product themselves. The three most frequently cited reasons for not using the therapy were no need (52%), no access (23%), and insufficient experience (19%). Informing the 37% of physicians who are not aware of FDA approval is an obvious target for program improvement. However, as many do not find a need for MDT, targeted improvements to MDT access and education for those physicians who encounter indications for MDT would permit them to apply MDT where there is an unmet need.